As one type of proximity wireless communication, there is wireless communication which is performed by NFC (Near field communication) that uses 13.56 MHz as a carrier frequency. On the other hand, a technology is also proposed which utilizes a coil used for NFC communication so as to perform non-contact power feeding by a magnetic field resonance method.
In the non-contact power feeding utilizing magnetic field resonance, a power transmission-side resonant circuit including a power transmission-side coil is arranged in a power transmission device, a power reception-side resonant circuit including a power reception-side coil is arranged in a power reception device and the resonant frequencies of the resonant circuits are set to a common reference frequency. An alternating current is then passed through the power transmission-side coil, and thus an alternating magnetic field at the reference frequency is generated in the power transmission-side coil. Then, the alternating magnetic field is transmitted to the power reception-side resonant circuit which resonates at the reference frequency, and thus an alternating current flows through the power reception-side coil. In other words, power is transmitted from the power transmission-side resonant circuit including the power transmission-side coil to the power reception-side resonant circuit including the power reception-side coil.